Web connection and paper machine fabric

ABSTRACT

A web connection for a fabric of a machine for producing or processing a fibrous material web includes a first web end with first longitudinal thread ends, a second web end with second longitudinal thread ends, and at least one connection element which extends in the transverse direction of the resultant fabric. The connection element has an upper face and a lower face, and the first longitudinal thread ends and the second longitudinal thread ends solely contact and bond to the upper face of the connection element, in particular the thread ends are welded thereto. The fabric with a paper side and a running side. The fabric has at least one first web layer with at least one such web connection which is arranged such that the lower face of the at least one connection element is oriented in the direction of the running side of the fabric.

The invention relates to a woven fabric connection and to a clothing and to a seam clothing of a machine for producing or processing a fibrous web.

Clothings, in particular clothings for paper machines, as a component part frequently comprise one or a plurality of woven fabric belts. Endless woven fabric belts, so-called belt loops, are usually required for use in a clothing. These can either be woven (“circular-woven”) directly as a belt loop, or they may be woven as a flat woven fabric piece which is rendered endless by connecting the two longitudinal ends.

In the prior art, various possibilities are known for such a connection between two ends of a woven fabric belt.

In this way, US 2014/0186579 describes the connecting of two ends by means of an ultrasonic weld seam. However, this type of connection is disadvantageous. On the one hand, the woven fabric suffers during the welding process, as can also be seen in the figures of US 2014/0186579. The post-welding properties of the joint cannot be readily predicted. The strength properties of the welded filaments also suffer. This is particularly disadvantageous because a sufficient tensile strength, in particular in the machine direction, represents an important quality feature of the basic woven fabric and of the finished clothing. Finally, welded connections of this type are also comparatively fracturable.

A welded connection of two woven fabric ends is also proposed in U.S. Pat. Nos. 7,381,307. 7,381,307 does not go into very great detail in terms of the welding of the ends but generally proposes laser welding as a suitable type of connection.

It is an object of the present invention to propose a woven fabric connection which is improved in comparison to the prior art, and an improved clothing having such a woven fabric connection.

The intention is to propose a strong woven fabric connection which is easy to produce.

It is furthermore an object of the invention to propose a woven fabric connection of which the properties can be adapted in a simple manner to the required specific application.

It is a further object to propose a clothing having a woven fabric connection, in which the woven fabric connection barely leaves marks in the fibrous web produced.

The objects are completely achieved by a woven fabric connection as claimed in claim 1 and by a clothing as claimed in claim 2 and by a seam clothing as claimed in claim 7.

Advantageous embodiments are described in the dependent claims.

When mention is made in the context of this application that an element is absorbent to light, for example laser light, of a specific wavelength, it is to be understood that at least 30%, preferably at least 50%, particularly preferably at least 70% of the irradiated energy is absorbed.

When mention is made in the context of this application that an element is transparent to light, for example laser light, of a specific wavelength, this is to be understood that at most 20%, preferably at most 10%, particular preferably at most 5% of the irradiated energy is absorbed.

When mention is made in the context of this application that an element has an upper side, or a lower side, respectively, this in the case of circular elements is to be understood that the semicircle above a centerline is understood to be the upper side, and the semicircle therebelow is understood to be the lower side.

The same applies in an analogous manner to elliptic or similar elements.

In terms of connection, the object is achieved by a woven fabric connection for a clothing of a machine for producing or processing a fibrous web, comprising a first woven fabric end having first longitudinal thread ends and a second woven fabric end having second longitudinal thread ends, and at least one connecting element which extends in the transverse direction of the subsequent clothing. It is provided according to the invention that the connecting element has an upper side and a lower side, and the first longitudinal thread ends and the second longitudinal thread ends are in contact exclusively with the upper side of the connecting element and are connected in a materially integral manner, in particular welded, to said upper side.

The feature that a longitudinal thread end is in contact exclusively with the upper side of the connecting element here is also to be considered met when a small part of the longitudinal thread end, for example as a consequence of a fusing procedure during welding, contacts a connecting element outside the upper side.

The machine can in particular be a paper machine (e.g. a cardboard machine, tissue machine) or a cellulosic pulp machine.

It is advantageous for the materially integral connection to be performed by means of transmission welding, in particular laser transmission welding. This method is advantageous in the field of clothings for paper or cellulosic pulp machines inter alia because these clothings are often entirely or partially composed of polyamides, and polyamides are largely transparent in the NIR wavelength range, for example. The welding can be carried out in a very simple manner by inserting entirely or partially absorbent connecting elements. Moreover, the non-absorbent parts of the clothing are not influenced, or influenced only to a very minor extent, by the welding process.

In advantageous embodiments of the woven fabric connection a plurality of connecting elements, in particular two or three connecting elements, can be provided. In this instance, the first and the second longitudinal thread ends can in particular in each case be in contact exclusively with the upper side of the connecting elements and be connected in a materially integral manner, in particular welded, to said connecting elements. By providing a plurality of connecting elements, the strength of the woven fabric connection can be increased on the one hand, while, on the other hand, the flexibility or else the permeability of the woven fabric connection is increased in comparison to the use of a single comparatively large connecting element.

It can furthermore be provided that, for generating the first longitudinal thread ends and/or the second longitudinal thread ends, one or a plurality of transverse threads, in particular 2 to 5 transverse threads, are in each case removed from the first woven fabric end and/or the second woven fabric end. This is particularly advantageous when a plurality of connecting elements are used, so as to generate longitudinal thread ends of sufficient length.

The connecting elements can advantageously extend across a plurality of longitudinal thread ends of one woven fabric end. The connecting elements will typically extend across the entire width of the woven fabric in the transverse direction.

In preferred embodiments it can be provided that at least one connecting element, preferably all connecting elements, is/are embodied as a thread. The thread, or the threads, respectively, in this instance can in particular have a circular, oval, or rectangular cross section. However, threads having other cross sections are also possible. By suitably shaping the cross section, for example so as to be X-shaped, Y-shaped or wedge-shaped, the compressibility and elasticity can also be varied in threads from a single material. Moreover, the contact area between the connecting elements and the longitudinal thread ends can be increased without generating an excessive material density in the woven fabric connection.

It is likewise possible that the connecting elements are not embodied as a thread. Alternatively, for example, it is also possible for some or all connecting elements to be embodied as a woven fabric belt or as foils/films or foam strips.

It can furthermore be provided that the diameter of the at least one connecting element is larger, in particular by more than 10%, preferably by more than 30%, than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.

If a plurality of connecting elements, in particular connecting threads, are used, it can be advantageous for the spacing between two adjacent connecting elements to be larger, in particular by more than 10%, preferably by more than 20%, than the spacing of adjacent transverse threads of the first woven fabric end and of the second woven fabric end.

The connecting, in particular welding, of woven fabric ends can be performed as described, by removing transverse threads at the woven fabric ends while configuring longitudinal thread ends that project from the woven fabric ends, by providing transverse threads and subsequently disposing the longitudinal thread ends above the provided transverse threads. An obvious embodiment would be to remove the same number of transverse threads (e.g. 3 pieces) at both woven fabric ends and to make available the same number (3 pieces) of connecting elements, in particular thread-shaped connecting elements, in the overlapping region of the longitudinal threads, ideally at almost the same spacing as defined by the non-depleted woven fabric.

Moreover, it appears to be obvious that transverse threads with the same diameters as the transverse threads in the woven fabric are used for the provided connecting elements.

If a transmission welding method is used for connecting, the inserted/provided transverse threads can moreover be embodied such that said transverse threads sufficiently absorb light of the wavelength that is used for welding.

However, it has been established that provided connecting elements with a larger diameter in comparison to the transverse threads in the non-depleted woven fabric of the woven fabric ends lead to more stable welded connections; the reason therefor being that the contact pressure force applied during the welding of the woven fabric ends better presses the longitudinal threads and transverse threads in the connecting region into one another and generally larger contact areas on the thread connections are generated. Nevertheless, woven fabric connections having only minimal variations in the thickness in comparison to the non-depleted woven fabric are obtained by simultaneous compressing and welding.

By way of example, woven fabric connections with transverse thread diameters of the connecting elements of 0.5 mm, instead of 0.4 mm for the transverse threads of the non-depleted woven fabric, and strengths of +30-90% were able to be attained. However, the thickness of the connecting zone was comparable in both cases and largely identical to the thickness of the non-depleted woven fabric.

A larger diameter of the connecting elements can also be advantageous when the woven fabric is to have a high storage volume and, therefore, is embodied as a woven fabric with 1.5 tiers or 2 tiers.

In the case of a 1.5-tier woven fabric, the threads running in the transverse direction can lie next to one another so densely that said threads as a result are slightly displaced upward and downward, a thicker and more voluminous woven fabric being created as a result, for example. If threads with the same diameter as the transverse threads of the woven fabric were to be used here as connecting element, which is possible in principle, the woven fabric seam would be thinner than the remaining woven fabric. Undesirable marks in the paper could be created as a result. A matching thickness of the woven fabric and of the woven fabric seam can be achieved by using correspondingly thicker threads as connecting elements.

Alternatively or additionally, it can moreover also be provided that threads of a different type are used for the connecting elements than for the transverse threads of the woven fabric. It can be provided in particular that twisted yarns are used for the transverse threads of the non-depleted woven fabric, and monofilaments are used for the connecting elements. This can be advantageous because welded connections can in most instances be implemented more easily and in a more reproducible manner when using monofilaments than twisted yarns. In one preferred embodiment, twisted yarns of the type 2×2×0.2 mm (2 filaments of 0.2 mm diameter are twisted with one another, and two of the twisted yarns thus created are subsequently twisted with one another again) are used for the transverse threads of the non-depleted woven fabric. Monofilaments with a diameter of 0.4 m can be used for the connecting elements here. Aside from this example described, however, a multiplicity of further combinations are also possible.

In advantageous embodiments it can be provided that the connecting elements, at least on the respective upper side thereof, are embodied to absorb light of a wavelength in the range between 780 μm and 1200 μm.

It has moreover been established that such woven fabric connections with connecting elements which have a spacing of the woven fabric ends that deviates from the spacings of the transverse threads in the non-depleted woven fabric are advantageous. For example, if 4 transverse threads are removed at the woven fabric ends, but only 3 transverse threads which are disposed largely at the same spacing in the connecting region are provided as connecting elements for the woven fabric connection, somewhat more open woven fabric connections are obtained after welding, which have a material density which is reduced in comparison to the connections described above.

Moreover, the connecting region which is relatively rigid per se (all longitudinal thread ends and all connecting elements are ideally welded to one another at all contact points) is somewhat more flexible. Both effects have an advantageous effect, for example when needle-punching the woven ground fabric tiers to fibrous non-woven tiers of a press felt. In the case of very dense woven fabric connections, the fiber transport during needle-punching is typically impeded.

Despite the higher material density there by virtue of the woven fabric connection, regions of the press felt that after needle-punching have a higher permeability in comparison to needle-punched regions in the non-depleted woven fabric are obtained. Fewer fibers are needle-punched into the woven fabric tier; non-woven fibers on the paper side are to some extent transported into adjacent regions during the needle-punching process, or as a result of being concentrated above the woven fabric tiers lead to thick places.

It can furthermore be provided that the connecting elements are deformable, in particular elastically deformable.

This can be implemented in particular in that the connecting elements comprise an elastomer, in particular a polyurethane.

In principle, the connecting elements can be from a uniform material, or be constructed from different materials. In this way, so-called core-casing threads can inter alia be used as connecting elements, wherein the core and the casing are composed of different materials. For example, it is possible here that the connecting elements have a core from a polyurethane which is surrounded by a casing of polymer material, wherein the casing is embodied to absorb light of a wavelength in the range between 780 μm and 1200 μm.

The casing here should be thick enough to avoid that the core material is exposed during or after welding. On the other hand, the casing should be sufficiently thick to enable the soft or elastic core to compress and expand again when the thread is under load.

As a potential alternative to the core-casing thread, so-called “top-bottom” elements, or “top-bottom” threads, may be used as connecting elements.

Such a thread has an absorbent upper side and a lower side which has good elastic properties. For example, a lower side from TPU (thermoplastic polyurethane) and an upper side from a polyamide, for example a PA6, which includes an absorber additive. Industrial carbon (“carbon black”) is very suitable as an absorber additive.

Further advantages of the ideas described here also lie in better anchoring of the fibers, and in an improved permeability profile.

Disclosed is a clothing for a machine for producing or processing a fibrous web, having a web-contacting paper side and a running side that faces away from the web, wherein the clothing comprises at least one first woven fabric tier which has at least one woven fabric connection according to one aspect of the invention described above.

In terms of the clothing, the object is achieved by a clothing for a machine for producing or processing a fibrous web, having a web-contacting paper side and a running side that faces away from the web, wherein the clothing has at least one first woven fabric tier. It is provided according to the invention that the first woven fabric tier has at least one woven fabric connection according to one aspect of the invention described above, wherein the woven fabric connection is disposed such that the lower side of the at least one connecting element is oriented in the direction of the running side of the clothing.

Advantageous embodiments of the clothing are described in the dependent claims.

A woven fabric tier of a clothing according to one aspect of the present invention can be composed of a woven fabric piece which is rendered endless by a single woven fabric connection, for example. In this instance, the woven fabric connection connects the two woven fabric ends of the same woven fabric piece to one another. This woven fabric piece can have the same woven fabric properties (e.g. weave pattern, thread thickness, thread density) across the entire extent thereof. It is, however, also possible that one property, e.g. the weave pattern, changes across the woven fabric piece. In this way, the weave pattern can change along the longitudinal direction of the woven fabric piece, for example.

In alternative embodiments it can be advantageous that the first woven fabric tier has a plurality of woven fabric connections which are constructed according to one of the aspects described above, wherein all woven fabric connections are in particular disposed such that the lower side of the respective connecting elements is oriented in the direction of the running side of the clothing. In this instance, the woven fabric connections connect the woven fabric ends of different woven fabric pieces to one another.

Here too, the individual woven fabric pieces can either be identical or differ in terms of one or a plurality of properties. In particular, the individual woven fabric pieces per se can have the same woven fabric properties (e.g. weave pattern, thread thickness, thread density) across the entire extent thereof. It is, however, also possible that one property, e.g. the weave pattern, changes across the woven fabric piece.

It can furthermore be advantageous for the clothing to have one or a plurality of further woven fabric tiers, wherein the latter can likewise have one or a plurality of woven fabric connections, in particular according to one of the aspects described above. The first woven fabric tier here is preferably disposed closer to the paper side of the clothing than the further woven fabric tiers.

In terms of the seam clothing, the object is achieved by a seam clothing for a machine for producing or processing a fibrous web, having a web-contacting paper side and a running side that faces away from the web, wherein the seam clothing comprises a basic structure which is implemented in that a woven fabric piece is folded at two fold locations and, while configuring a two-tier woven fabric, is deposited onto itself, wherein the two woven fabric ends are connected to one another by a woven fabric connection, and wherein seam loops are formed at the fold locations, wherein an endless woven fabric loop is generated by connecting the seam loops by means of a pintle element so as to form a pintle seam. It is provided according to the invention that the woven fabric connection is embodied according to one aspect of the invention described above, and the woven fabric connection is disposed such that the lower side of the at least one connecting element points in the direction of the interior of the two-tier woven fabric being created.

Here too, advantageous embodiments are set forth in the dependent claims.

In this way, it can be provided, for example, that the woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the paper side, wherein the lower side of the connecting element is oriented in the direction of the running side of the clothing.

As a result of the woven fabric connection being disposed in that tier that is closer to the paper side, the woven fabric connection does not come into direct contact with the driving, guiding or dewatering elements of the paper machine during the operation of the seam clothing. The woven fabric connection is protected in this way and is subject to less wear. This is particularly advantageous because the materially integral connection, in particular in the embodiment as a welded connection, can break under permanent stress by these elements, above all when the driving, guiding or dewatering elements engage on the side of the connecting element.

Such an embodiment is therefore particularly advantageous in such applications in which a high risk of wear is to be anticipated by virtue of the machine construction or the machine running mode.

Alternatively, it can be provided that the woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the running side, wherein the lower side of the connecting element is oriented in the direction of the paper side of the clothing.

As a result of this arrangement, the woven fabric connection is separated from the fibrous web at least by the second tier of the woven fabric. As a result, the marking tendency of the woven fabric connection can be significantly reduced. In order for the woven fabric connection to be protected against wear, the latter is oriented such that the connecting element/elements is/are oriented inward, i.e. away from the driving, guiding or dewatering elements of the paper machine.

Such an embodiment is particularly advantageous in such applications in which, owing to the spectrum of varieties produced, even slight marks by the seam clothing can already lead to significant quality shortcomings.

Alternatively or additionally, it can be provided that the clothing and/or the seam clothing have/has at least one further woven fabric tier, wherein the further woven fabric tier is a circular-woven fabric tier.

In preferred embodiments the clothing or the seam clothing can be a press felt in which the paper side of the clothing is provided by a non-woven tier which is connected to the woven fabric tier/tiers by needle-punching.

The following sentences serve once again for describing various aspects of the invention:

Sentence 1. Woven fabric connection for a clothing of a machine for producing or processing a fibrous web, comprising a first woven fabric end having first longitudinal thread ends and a second woven fabric end having second longitudinal thread ends, and at least one connecting element which extends in the transverse direction of the subsequent clothing, characterized in that the connecting element has an upper side and a lower side, and the first longitudinal thread ends and the second longitudinal thread ends are in contact exclusively with the upper side of the connecting element and are connected in a materially integral manner, in particular welded, to said upper side.

Sentence 2. Woven fabric connection according to one of the preceding sentences, characterized in that a plurality of connecting elements, in particular two or three connecting elements, are provided and the first longitudinal thread ends and the second longitudinal thread ends are in each case in contact exclusively with the upper side of the connecting elements and are connected in a materially integral manner, in particular welded, to said upper side.

Sentence 3. Woven fabric connection according to one of the preceding sentences, characterized in that for generating the first longitudinal thread ends and/or the second longitudinal thread ends, one or a plurality of transverse threads, in particular 2 to 5 transverse threads, are in each case removed from the first woven fabric end and/or the second woven fabric end.

Sentence 4. Woven fabric connection according to one of the preceding sentences, characterized in that at least one connecting element, preferably all connecting elements, is/are embodied as a thread.

Sentence 5. Woven fabric connection according to sentence 4, characterized in that the thread has a circular, oval, or rectangular cross section.

Sentence 6. Woven fabric connection according to one of the preceding sentences, characterized in that the diameter of the at least one connecting element is larger, in particular by more than 10%, preferably by more than 30%, than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.

Sentence 7. Woven fabric connection according to one of sentences 2 to 6, characterized in that the spacing of two adjacent connecting elements is larger, in particular by more than 10%, preferably by more than 20%, than the spacing of adjacent transverse threads of the first woven fabric end and of the second woven fabric end.

Sentence 8. Woven fabric connection according to one of the preceding sentences, characterized in that the connecting elements at least on the respective upper side thereof are embodied to absorb light of a wavelength in the range between 780 μm and 1200 μm.

Sentence 9. Woven fabric connection according to one of the preceding sentences, characterized in that the connecting elements are deformable, in particular elastically deformable.

Sentence 10. Woven fabric connection according to one of the preceding sentences, characterized in that the connecting elements comprise an elastomer, in particular a polyurethane.

Sentence 11. Woven fabric connection according to one of the preceding sentences, characterized in that the connecting elements have a core from a polyurethane, which is surrounded by a casing from polymer material, wherein the casing is embodied so as to absorb light of a wavelength in the range between 780 μm and 1200 μm.

Sentence 12. Clothing for a machine for producing or processing a fibrous web, having a web-contacting paper side and a running side that faces away from the web, wherein the clothing has at least one first woven fabric tier, characterized in that the first woven fabric tier has at least one woven fabric connection according to one of the preceding sentences, wherein the woven fabric connection can in particular be disposed such that the lower side of the at least one connecting element is oriented in the direction of the running side of the clothing. (In principle, other arrangements are also possible, cf. FIG. 7 e , for example).

Sentence 13. Clothing according to sentence 12, characterized in that the first woven fabric tier has a plurality of woven fabric connections according to one of sentences 1 to 11, wherein all woven fabric connections are disposed such that the lower side of the respective connecting elements is oriented in the direction of the running side of the clothing.

Sentence 14. Clothing according to one of sentences 12 to 13, characterized in that the clothing has one or a plurality of further woven fabric tiers which likewise have a woven fabric connection, in particular according to one of sentences 1 to 11, wherein the first woven fabric tier is disposed closer to the paper side of the clothing than the further woven fabric tiers.

Sentence 15. Clothing according to one of sentences 12 to 14, characterized in that the clothing has at least one further woven fabric tier, wherein the further woven fabric tier is a circular-woven fabric tier.

Sentence 16. Clothing according to one of sentences 12 to 15, characterized in that said clothing is a press felt, wherein the paper side of the clothing is provided by a non-woven tier which is connected to the woven fabric tier/tiers by needle-punching.

The invention will be explained in further detail hereunder by means of schematic figures in which:

FIGS. 1 a and 1 b explain a woven fabric connection according to one aspect of the present invention;

FIG. 2 shows a woven fabric connection according to a further aspect of the invention;

FIGS. 3 a to 3 d show cross sections of potential connecting elements according to various aspects of the invention;

FIG. 4 shows further potential cross sections for connecting elements according to various aspects of the invention;

FIG. 5 shows a clothing according to a further aspect of the invention;

FIGS. 6 a and 6 b each show a clothing according to a further aspect of the invention; and

FIGS. 7 a to 7 e show a potential production process for a woven basic structure for a clothing, in particular according to one aspect of the present invention.

FIG. 1 a shows a first woven fabric end 2 a and a second woven fabric end 2 b, which are to be connected by means of a woven fabric connection 1. This here can be, for example, two ends of a single woven fabric piece which is rendered endless by the woven fabric connection. However, this can also be woven fabric ends 2 a, 2 b of two different woven fabric pieces, which are joined by the woven fabric connection 1.

The first woven fabric end 2 a here has first longitudinal thread ends 3 a, and the second woven fabric end 2 b here has second longitudinal thread ends 3 b. In order to generate longitudinal thread ends 3 a, 3 b of sufficient length for the woven fabric connection 1, some transverse threads 6 of the non-depleted woven fabric have been removed at the two woven fabric ends 2 a, 2 b. It is often advantageous for between two and five transverse threads 6 to be removed per woven fabric end 2 a, 2 b.

It is shown in FIG. 1 b how the two woven fabric ends 2 a, 2 b from FIG. 1 a are combined. Provided here are three connecting elements 4 in the form of connecting threads 4 which run in the transverse direction of the subsequent clothing.

The connecting elements 4 here have an upper side 4 a and a lower side. The first longitudinal thread ends 3 a and the second longitudinal thread ends 3 b are disposed such that said longitudinal thread ends 3 a, 3 b are in contact exclusively with the upper sides 4 a of the connecting elements 4. For producing the woven fabric connection 1, the connecting elements 4 are connected in a materially integral manner to the upper sides 4 a of the connecting elements 4. The materially integral connection can advantageously be generated by welding, in particular by (laser) transmission welding. If the longitudinal thread ends 3 a, 3 b are from a polyamide, as is customary in many clothings, said longitudinal thread ends 3 a, 3 b are entirely or largely transparent to light in the NIR range. If at least the upper side 4 a of the connecting elements 4 is designed to be absorbent to light from this range, for example by adding a suitable absorber additive such as carbon black—the longitudinal thread ends 3 a, 3 b can be radiated with a suitable NIR laser light, the absorbent upper sides 4 a of the connecting elements 4 being heated and welded to the longitudinal thread ends 3 a, 3 b. The process is usually carried out by applying a specific joining pressure.

Alternatively however, the material integral connection can also, for example, be implemented by other welding methods such as ultrasonic welding, or adhesively bonded connections.

The woven fabric connection 1 shown in FIG. 2 is a special embodiment of the woven fabric connection 1 from FIG. 1 b . The connecting elements 4 here are embodied in the form of connecting threads 4 which have a larger diameter in comparison to transverse threads 6 in the non-depleted woven fabric of the woven fabric ends 2 a, 2 b. This leads to more stable welded connections, the reason for the latter being that the contact pressure force applied when welding the woven fabric ends 2 a, 2 b better presses the longitudinal thread ends 3 a, 3 b and the connecting elements 4 into one another in the connecting region, and generally larger contact areas on the thread connections are generated. Nevertheless, woven fabric connections 1 having only minimal deviations in terms of the thickness in comparison to the non-depleted woven fabric are obtained by simultaneously compressing and welding.

In this way, woven fabric connections 1 having connecting elements 4 with diameters of 0.5 mm instead of 0.4 mm for the transverse threads 6 of the non-depleted woven fabric, and strengths increased by 30-90%, can be obtained, for example. However, the thickness of the connecting zone 1 was comparable in both cases and largely identical to the thickness of the non-depleted woven fabric.

Another example is a 1.5-tier or 2-tier woven fabric in which, for example, the threads running in the transverse direction lie next to one another so densely that said threads as a result are slightly disposed upward and downward, as a result of which a thicker and more voluminous woven fabric is created. As a result, in the case of transverse threads 6 and longitudinal threads of the longitudinal thread ends 3 a, 3 b with a diameter of in each case, for example, 0.4 mm, the woven fabric per se can have a thickness of 1.2 mm, for example. (The diameters stated are to be understood only as exemplary potential values. The invention is however not limited to these values). If threads with a diameter of 0.4 mm were likewise to be used as connecting elements 4 here, the thickness of the woven fabric connection, being about 0.8 mm, would be significantly less than that of the remaining woven fabric. This can lead inter alia to undesirable marks in the paper produced.

A solution here can also lie in the use of thicker connecting elements 4. In the case of a diameter of the connecting elements of 0.8 mm, conjointly with the diameter of the longitudinal thread ends 3 a, 3 b of 0.4 mm, this results in 1.2 mm and thus the same thickness for the woven fabric connection as for the woven fabric. As has been described above, the diameter of the connecting elements 6 may even be slightly (e.g. 10% or 20%) more. As a result of simultaneous compressing and welding, woven fabric connections 1 having only minimal deviations in terms of the thickness in comparison to the non-depleted woven fabric are also obtained again.

While woven fabric connections 1 having the desired thicknesses can be generated as a result, it may however arise on occasions that the woven fabric connection 1 thus created, as a result of the comparatively thick connecting elements 4, is quite heavy, or else hard, and especially also quite non-compressible, in comparison to the non-depleted woven fabric. This can be alleviated in that the connecting elements 4 by a suitable choice of the material (e.g. while using an elastomer), and/or by suitable shaping of the cross sections thereof, are provided with a certain elasticity. Examples to this end are advantageously shown in FIGS. 3 a-3 d and 4.

Moreover, the connecting elements 4 in FIG. 2 have been inserted at a spacing which is larger than the spacing of the transverse threads 6 in the non-depleted woven fabric of the woven fabric end 2 a, 2 b. In order for the longitudinal thread ends 3 a, 3 b to be generated here, four transverse threads 6 at the woven fabric ends 2 a, 2 b have been in each case removed in an exemplary manner, but only 3 transverse threads have been inserted as connecting elements 4 for the woven fabric connection 4. As a result, somewhat more open woven fabric connections 1 which have a reduced material density are received upon connecting.

Moreover, the connecting region 1 which is relatively rigid per se (all longitudinal thread ends 3 a, 3 b and all connecting elements 4 are ideally welded to one another at all contact points) is somewhat more flexible. Both effects have an advantageous effect, for example when needle-punching the woven ground fabric tiers to fibrous non-woven tiers of a press felt.

In order to be able to carry out the material integral connection efficiently by means of laser transmission welding, it is advantageous for the connecting elements 4 at least on the upper side 4 a thereof to be embodied so as to be absorbent. As has already been described above, to this end the entire connecting element can be embodied so as to be absorbent by means of an absorber additive. However, it is also possible for only parts of the connecting element 4 to be absorbent. FIG. 3 a shows a classic core/casing thread in which only the casing 8 is absorbent while there is a relatively large degree of freedom in the design of the core 7. This core can again be from a polyamide, for example. However, it is also possible for the core 7 to be made from other materials, for example an elastomer polyurethane. The elastic properties of the connecting element 4, which are increased as a result, can prove advantageous.

FIGS. 3 b, 3 c, and 3 d show variants of these connecting elements 4 from mixed materials.

To be seen in FIGS. 3 b and 3 c are “half-and-half” threads 4, once having a round cross section, and once having a rectangular cross section. The upper part, for example the upper half, here is from an absorbent casing material 8, and the lower part is from a non-absorbent core material 7.

FIG. 3 d shows a variant of FIG. 3 c . In the case of a rectangular connecting element 4 here, only the surface of the upper side 4 a is from an absorbent material 8. The latter can be applied to the connecting element prior to welding, for example. Suitable materials are commercially available under the trade name “Clearweld”, for example.

The connecting elements 4 shown here are intended only to demonstrate the diversity of possibilities. The invention is not limited to these examples.

FIG. 4 shows further potential cross sections for the connecting elements 4 according to various aspects of the invention. The compressibility and elasticity can be varied also in the case of threads from a single material by way of suitable shaping, for example in the shape of an X, a Y, or a wedge. Moreover, the contact area of the connecting elements having the longitudinal thread ends can be increased without generating an excess of material density in the woven fabric connection.

Alternatively however, connecting elements 4 shaped in such a manner as shown in FIG. 4 can have a core 7 which is surrounded by an absorbent casing material 8.

FIG. 5 shows a clothing 10 according to a further aspect of the invention. The clothing 10 is embodied as a press felt. Said clothing 10 comprises a non-woven tier 13 which makes available the paper side 11 of the clothing 10. The non-woven tier 13 is disposed on a first woven fabric tier 14 and fastened by needle-punching, for example. The first woven fabric tier 14 here has a woven fabric connection 1 which connects a first woven fabric end 2 a having first longitudinal thread ends 3 a and a second woven fabric end 2 b having second longitudinal thread ends 3 b to one another. Provided to this end in the clothing 10 of FIG. 5 are three connecting elements 4 which extend in the transverse direction of the clothing 10. The connecting elements 4 here are materially connected, in particular welded, to the first longitudinal thread ends 3 a and the second longitudinal thread ends 3 b exclusively by way of the upper side 5 of said connecting elements 4.

The woven fabric connection 1 is disposed such that the lower side 5 b of the connecting elements 4 is oriented in the direction of the running side 12 of the clothing 10. This arrangement of the woven fabric connection 1 influences the marking tendency of the press felt 10. The, optionally overlapping, longitudinal thread ends 3 a, 3 b point toward the paper side 13, and the transversely disposed threads of the connecting elements 4 point toward the running side 12. As a result of the relatively densely packed longitudinal threads 3 a, 3 b (approx. double the threaded density in the connecting region 1), potential mechanical marks emanating from the connecting elements 4 are minimized. This is all the more important because the transverse threads of the connecting elements 4 in advantageous embodiments have a larger mutual spacing than the transverse threads 6 in the non-depleted woven fabric.

Examples of clothings 10 according to further aspect of the present invention are also shown in FIGS. 6 a and 6 b . As opposed to FIG. 5 however, the clothings 10 shown here, or additionally to the first woven fabric tier 14, have in each case one further woven fabric tier 15, wherein the first woven fabric tier 14 is disposed closer to the paper side 11 of the clothing 10 than the further woven fabric tiers 15. The further woven fabric tiers 15 in these illustrations likewise have at least one woven fabric connection 1 according to one aspect of the present idea. In the clothings 10 shown in FIGS. 6 a and 6 b , these woven fabric connections 1 are disposed substantially on top of one another. However, it can frequently be advantageous for the woven fabric connections 1 of the first woven fabric tier 14 and the woven fabric connections 1 of the further woven fabric tier 15 not to be disposed directly on top of one another but to be mutually offset in the machine longitudinal direction (MD) and to have an MD spacing of more than 10 cm or more than 100 cm, for example.

The difference between FIG. 6 a and FIG. 6 b lies in the orientation of the woven fabric connection 1 in the further woven fabric tier 15. In the clothing 10 of FIG. 6 a the woven fabric connection 1 is oriented like the first woven fabric tier 14. The longitudinal thread ends 3 a, 3 b point toward the paper side 13, and the transversely disposed threads of the connecting elements 4 point toward the running side 12. In contrast, in the clothing 10 of FIG. 6 b the woven fabric connection 1 is oriented exactly the opposite way. Such an arrangement of the woven fabric connections 1 can in many cases be favorable from the point of view of production technology. In this way, the woven fabric connection 1 of the further woven fabric tier 15 can be closed simply by transmission welding, for example, in that the connecting region is irradiated with laser light from the running side, for example. This light can then penetrate the usually transparent longitudinal thread ends 3 a, 3 b and is absorbed by the upper sides 5 of the connecting elements, as a result of which the materially integral connection is generated. In the embodiment as in FIG. 6 this is not possible because the energy would be absorbed by the lower sides 5 b of the connecting elements 6. Welding of the upper sides 5 to the longitudinal thread ends 3 a, 3 b is thus impossible.

FIGS. 7 a to 7 e show a potential production process for a woven basic structure for a clothing 10, in particular for a clothing 10 according to one aspect of the present invention.

A woven fabric piece in the process is folded at two fold locations 20 and deposited onto itself such that the two woven fabric ends 2 a, 2 b touch or overlap one another (FIGS. 7 a and 7 b ). The two woven fabric ends 2 a, 2 b subsequently are connected to one another by a woven fabric connection 1. To this end, the longitudinal thread ends 3 a, 3 b by way of one or a plurality of connecting elements 4 are usually connected to one another in a materially integral manner. The connecting elements 4, in the form of threads, extend in the transverse direction of the clothing 10, for example. The connection here is performed in such a manner that the longitudinal thread ends 3 a, 3 b are in contact exclusively with the upper side of the connecting element 4, or the connecting elements 4, and are connected in a materially integral manner, in particular welded, to the latter. In order for the woven fabric connection to be adapted, a number of transverse threads 6 can be removed from the woven fabric ends 2 a, 2 b so as to increase the length of the longitudinal thread ends 3 a, 3 b. As is shown in FIG. 7 c , the woven fabric connection 1 is advantageously oriented such that the lower side 5 b of the at least one connecting element 4 points in the direction of the interior of the two-tier woven fabric being created. As has already been described, the materially integral connections can thus be implemented simply by means of transmission welding.

For producing a seam clothing 10, in particular of a press felt 10, seam loops 21 are formed at the fold locations 20. To this end, a certain number of transverse threads 6 are removed from the woven fabric at these locations. This removal often takes place prior to folding and depositing the clothing 10 onto itself.

By combining the seam loops 21 and connecting the latter by means of a pintle element so as to form a pintle seam 22, an endless woven fabric loop can be produced from the two-tier woven fabric, said endless woven fabric loop being able to be used as a basic structure for a clothing 10. The two possibilities shown in FIGS. 7 d and 7 e are available here.

In FIG. 7 d , the seam loops 21 have been combined such that the woven fabric connection 1 is disposed in that tier that is closer to the paper side 11. It results in the process that the woven fabric connection 1 is disposed such that the lower side 5 b of the at least one connecting element 4 is oriented in the direction of the running side 12 of the clothing 10. Such a woven fabric loop as in FIG. 7 d can thus also be used as the first woven fabric tier 14 in a clothing 10 according to one aspect of the invention.

An alternative is shown in FIG. 7 e . The seam loops 21 here have been combined such that the woven fabric connection 1 is disposed in that tier that is closer to the running side 12. It results in the process that the woven fabric connection 1 is disposed such that the lower side 5 b of the at least one connecting element 4 is oriented in the direction of the paper side 11 of the clothing 10. Such a woven fabric loop as shown in FIG. 7 e , not least owing to the simple production thereof, can also be advantageously used as the woven fabric tier 14, optionally also as the first woven fabric tier, in a clothing 10.

LIST OF REFERENCE SIGNS

-   -   1 Woven fabric connection     -   2 a First woven fabric end     -   2 b Second woven fabric end     -   3 a First longitudinal thread end     -   3 b Second longitudinal thread end     -   4 Connecting element     -   5 Upper side     -   5 b Lower side     -   6 Transverse threads     -   7 Core     -   8 Casing     -   10 Clothing     -   11 Paper side     -   12 Running side     -   13 Non-woven tier     -   14 First woven fabric tier     -   15 Further woven fabric tier     -   20 Fold location     -   21 Seam loop     -   22 Pintle seam 

1-9. (canceled)
 10. A woven fabric connection for a clothing of a machine for producing or processing a fibrous web, the woven fabric connection comprising: a first woven fabric end having first longitudinal thread ends and a second woven fabric end having second longitudinal thread ends, and at least one connecting element which extends in a transverse direction of the clothing to be formed; said at least one connecting element having an upper side and a lower side; said first longitudinal thread ends and said second longitudinal thread ends being in contact exclusively with said upper side of said at least one connecting element; and said first longitudinal thread ends and said second longitudinal thread ends being connected in a materially integral manner to said upper side of said at least one connecting element.
 11. The woven fabric connection according to claim 10, wherein said first and second longitudinal thread ends are welded to said upper side.
 12. The woven fabric connection according to claim 10, wherein said at least one connecting element is one of a plurality of connecting elements, and said first and second longitudinal thread ends are in each case in contact exclusively with said upper side of said connecting elements and are connected in the materially integral manner to said connecting elements.
 13. The woven fabric connection according to claim 12, wherein said plurality of connecting elements are two or three connecting elements.
 14. The woven fabric connection according to claim 12, wherein all of said connecting elements are threads.
 15. The woven fabric connection according to claim 10, wherein said at least one connecting element is a thread.
 16. The woven fabric connection according to claim 10, wherein a diameter of said at least one connecting element is larger than a diameter of the interwoven transverse threads of said first woven fabric end and of said second woven fabric end.
 17. The woven fabric connection according to claim 16, wherein the diameter of said at least one connecting element is greater by more than 10% than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.
 18. The woven fabric connection according to claim 16, wherein the diameter of said at least one connecting element is greater by more than 30% than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.
 19. A clothing for a machine for producing or processing a fibrous web, the clothing comprising: a web-contacting paper side and a running side facing away from the web to be produced or processed; at least one first woven fabric tier having at least one woven fabric connection according to claim 10; said at least one woven fabric connection being disposed with the lower side of the at least one connecting element being oriented in the direction of said running side of the clothing.
 20. The clothing according to claim 19, wherein said first woven fabric tier has a plurality of said woven fabric connections, and wherein all of said woven fabric connections are disposed with the lower side of the respective said connecting elements being oriented in the direction of said running side of the clothing.
 21. The clothing according to claim 19, further comprising at least one or a plurality of further woven fabric tiers which likewise have a respective said woven fabric connection, wherein the first woven fabric tier is disposed closer to the paper side of the clothing than the further woven fabric tiers.
 22. The clothing according to claim 19, further comprising at least one further woven fabric tier being a circular-woven fabric tier.
 23. The clothing according to claim 19, wherein the clothing is a press felt and the paper side of the clothing is a non-woven tier which is connected to said first woven fabric tier by needle-punching.
 24. A seam clothing for a machine for producing or processing a fibrous web, the clothing comprising: a web-contacting paper side and a running side facing away from the web; a basic structure formed by a woven fabric piece being folded at two fold locations and deposited onto itself to configure a two-tier woven fabric; said woven fabric piece having two woven fabric ends connected to one another by a woven fabric connection according to claim 10; wherein seam loops are formed at the fold locations and wherein an endless woven fabric loop is generated by connecting the seam loops by a pintle element to form a pintle seam; said woven fabric connection being disposed such that the lower side of the at least one connecting element is facing in the direction of an interior of the two-tier woven fabric.
 25. The seam clothing according to claim 24, wherein said woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the paper side of the clothing, and wherein a lower side of the connecting element is oriented in a direction of the running side of the clothing.
 26. The seam clothing according to claim 24, wherein said woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the running side, and wherein the lower side of the connecting element is oriented in a direction of the paper side of the clothing. 